Fertilizing method for realizing binary synergistic enrichment of zinc and selenium in wheat grains

Abstract

The invention discloses a fertilizing method for realizing binary synergistic enrichment of zinc and selenium in wheat grains. Relates to the technical field of wheat nutrition fertilization. Comprising the following steps: 1) applying a zinc fertilizer; 2) applying a base fertilizer; humic acid; an organic fertilizer; a calcium-magnesium-sulfur-silicon fertilizer; 3) topdressing; unmanned aerial vehicle foliage fertilizer spraying: 21) unmanned aerial vehicle foliage selenium spraying: spraying a selenium fertilizer in a wheat heading stage; and 22) spraying zinc on leaf surfaces by the unmanned aerial vehicle: spraying a zinc fertilizer. According to the invention, a wheat grain zinc and selenium binary synergistic enrichment soil-leaf surface comprehensive fertilization technology is innovatively formed; large-area foliar zinc fertilizer spraying operation is carried out through the unmanned aerial vehicle, the zinc concentration of wheat grains is greatly improved, meanwhile, the operation efficiency is greatly improved, the inherent cognition on the traditional foliar zinc fertilizer spraying concentration is broken through, and optimization updating and iterative upgrading of technical parameters are achieved; a comprehensive regulation and control technology is formed from soil to leaf surfaces, and soil fertility improvement, stress resistance and yield increase and wheat grain microelement nutritional quality improvement are coordinated.

Description

Technical Field

[0001] The present invention relates to the technical field of wheat nutrient fertilization, and more specifically, to a fertilization method for realizing the binary synergistic enrichment of zinc and selenium in wheat grains. Background Art

[0002] Soil types in China are diverse, and more than 50% of the soil is in a state of zinc and selenium deficiency, mainly including calcareous soils with a relatively high calcium carbonate content, saline-alkali soils with a relatively high pH value, and soils with a relatively light texture, etc. Low soil organic matter content, drought, water shortage, and low temperature and other factors will all lead to low available zinc and selenium content in the soil. In addition, the increase in crop yield levels takes away more zinc and selenium from the soil. Coupled with the excessive application of phosphorus causing phosphorus-zinc antagonism, it leads to the imbalance of macro, medium, and microelement nutrients, further exacerbating the risk of deficiency of trace elements such as zinc in the soil and crops, and also restricting the large-scale increase in wheat yield per unit area.

[0003] For a long time, the application of micronutrient fertilizers such as zinc and selenium has not been fully emphasized, and there is a lack of reasonable application technical regulations in agricultural production. Farmers often apply micronutrient fertilizers blindly, resulting in improper application, such as excessive or insufficient dosage, inappropriate application period, etc., thus affecting the application effect of micronutrient fertilizers and unable to fully exert the potential of micronutrient fertilizers.

[0004] In summary, the problems that have existed in wheat production for a long time include: (1) serious deficiency of trace elements such as zinc and selenium in the soil, imbalance of macro, medium, and microelement nutrients, restricting the large-scale increase in wheat yield per unit area; (2) the zinc content in grains is generally low, far lower than the requirement of the grain zinc content ≥ 45 mg / kg specified in the agricultural industry standard "Zinc Biofortified Wheat" NY / T 4340-2023, and the selenium content in grains is generally low, far lower than the requirement of the grain selenium content ≥ 150 μg / kg generally specified in the production of selenium-rich wheat; (3) there is a contradiction between high-yield varieties and high-quality micronutrient nutrition in grains, that is, the "dilution effect" generally exists, and the concentrations of zinc and selenium in wheat grains in production are both low. Especially in calcareous calcareous alkaline soils, the average concentration of grain zinc is lower than 35 mg / kg, and the average concentration of selenium is lower than 50 μg / kg. It is difficult to breed high-yield, high-quality, widely adaptable varieties that are both high-yielding and have the concentrations of zinc and selenium in grains meeting the requirements in (2) through breeding in the short term. The breeding approach has a long cycle and slow results.

[0005] In view of the above problems of lack of available zinc and selenium in the soil, mismatch with the application of macronutrient fertilizers such as nitrogen and phosphorus, imbalance of macro, medium, and microelement nutrients, generally low concentrations of zinc and selenium in grains, and the contradiction between high-yield varieties and high-quality micronutrient nutrition in grains, the solutions in the prior art mainly include the following three:

[0006] (1) Applying zinc fertilizer and selenium fertilizer to the soil alone; (2) Spraying zinc fertilizer (traditional plant protection machinery includes small sprayers, manual backpack sprayers, etc.) and selenium fertilizer (sprayed by drones) on the leaves alone; (3) Applying zinc fertilizer or selenium fertilizer alone in combination of soil and leaves; and only one micronutrient fertilizer is applied in the same growing season in these three schemes.

[0007] However, the above three existing schemes mainly have the following disadvantages:

[0008] (1) Only paying close attention to the application of one trace element, such as zinc or selenium;

[0009] (2) In terms of soil fertilization, it is not applied in combination with macronutrients such as carbon (humic acid and organic fertilizer, etc.), nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and silicon;

[0010] (3) When spraying zinc fertilizer on the leaves, traditional plant protection machinery (small sprayers, backpack sprayers, etc.) is used for operation, with low efficiency, and technical parameters such as the spraying concentration and water consumption of leaf zinc fertilizer can no longer meet the operation requirements of modern drones and urgently need to be updated.

[0011] Therefore, the existing schemes have a low wheat yield increase, usually in the range of 5% - 10%, rarely exceeding 10%, and cannot achieve the simultaneous increase in the concentrations of zinc and selenium in grains, that is, binary synergistic enrichment. Moreover, the increase in the concentration of zinc in grains is low, and the concentration value cannot be guaranteed to reach 45 mg / kg, which cannot meet the requirement of the grain zinc content ≥ 45 mg / kg specified in the agricultural industry standard "Zinc Biofortified Wheat" NY / T 4340 - 2023.

[0012] Therefore, whether there is a fertilization method that can achieve binary synergistic enrichment of zinc and selenium in wheat grains and overcome the above technical deficiencies is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0013] In view of this, the present invention provides a fertilization method for achieving binary synergistic enrichment of zinc and selenium in wheat grains. Through reasonable fertilization, that is, the reasonable matching of macro, medium, and trace elements (such as carbon, nitrogen, phosphorus, zinc, and selenium), on calcareous calcareous alkaline soil, the simultaneous increase of wheat grain yield and the two trace elements zinc and selenium in grains is achieved, and the contradiction between high yield and high-quality trace element nutrition is solved.

[0014] In order to achieve the above object, the present invention adopts the following technical scheme:

[0015] A fertilization method for achieving binary synergistic enrichment of zinc and selenium in wheat grains, comprising the following steps:

[0016] (1) Soil fertilization:

[0017] 1) Applying zinc fertilizer;

[0018] 2) Application of base fertilizer: Application of low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer, with the requirements of N ≥ 20%, 7% ≤ P2O5 ≤ 12%, K2O ≤ 13%);

[0019] Humic acid;

[0020] Organic fertilizer;

[0021] Calcium-magnesium-sulfur-silicon fertilizer;

[0022] 3) Top dressing;

[0023] (2) UAV foliar fertilizer spraying:

[0024] 21) UAV foliar spraying of selenium: Spraying selenium fertilizer on wheat during heading period;

[0025] 22) Drone zinc foliar spraying: spraying zinc fertilizer.

[0026] Preferably: Step 1) is to apply ZnSO4·7H2O as a base at 2-3 kg / mu, which is applied once before sowing by plowing;

[0027] Step 2) low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer: compound fertilizer N-P2O5-K2O ratio is 25-10-10, 26-7-7 or 26-10-8, 45-50 kg / mu, applied once;

[0028] Organic matter content 85% humic acid: 10-20kg / mu;

[0029] Organic fertilizer 50-100 kg / mu;

[0030] Calcium-magnesium-sulfur-silicon fertilizer application: 10-20 kg / mu;

[0031] 3) Top dressing: Apply urea at a rate of 10-15 kg / mu during the greening / jointing period, and apply once.

[0032] Preferably: step 21) spraying sodium selenite 5-10g / mu, water carrying capacity 5-10L / mu, adding v / v 0.01% Tween 20; spraying once again 10 days after flowering, a total of 2 times of spraying selenium fertilizer;

[0033] Step 22) is specifically as follows: spray 3-6% ZnSO4·7H2O 3-5 L / mu, add v / v 0.01% Tween 20, accumulating 4 times at 5 days, 15 days, 20 days and 25 days after flowering.

[0034] Preferably: in step 2), the organic fertilizer is replaced with farmyard manure at a rate of 300-400 kg / mu.

[0035] Preferably, in the topdressing stage of step 3), if the wheat shows symptoms such as dwarfing and clustering, small leaves, distorted or wrinkled leaf margins, and yellowing from green on both sides of the leaf veins, promptly topdress 1 - 2 kg / acre of ZnSO4·H2O / ZnSO4·7H2O; in areas with integrated water and fertilizer conditions, during the seedling stage to jointing stage, topdress 1 - 2 times, 0.5 kg / acre of ZnSO4·7H2O each time, and apply it simultaneously with urea or water-soluble fertilizers.

[0036] When the irrigation water quality is alkaline, the pH value needs to be adjusted to the range of 5.5 - 6.0 before adding ZnSO4·7H2O.

[0037] Preferably, in step (2), for foliar spraying of fertilizer by drone: if the wheat shows zinc deficiency symptoms at the seedling stage, spray ZnSO4·7H2O on the leaves, spray 1 - 2 times, with an interval of 5 - 7 days each time; during the growth period, if it encounters adversity hazards such as drought, low-temperature cold snap in spring, and high-temperature and dry hot wind in the later stage, which affect the normal growth and development of the plants, spray 1 - 2 times, with an interval of 5 - 7 days each time.

[0038] Preferably, when the step of foliar spraying zinc by drone is replaced by foliar spraying zinc with traditional plant protection machinery, manual backpack sprayers or small sprayers, spray 0.3% - 0.5% ZnSO4·7H2O, and the amount of fertilizer solution used is 40 L / acre - 50 L / acre.

[0039] The present invention also provides the application of any of the above fertilization methods in agricultural production.

[0040] Furthermore, for foliar spraying of fertilizer by drone, selenium fertilizer or zinc fertilizer can also be mixed and sprayed with non-alkaline substances such as urea solution or other water-soluble foliar fertilizers (such as amino acid-containing and humic acid-containing water-soluble fertilizers), drought inhibitors, and pesticides. The spraying concentration of selenium or zinc fertilizer should preferably use the lower limit, and if sprayed alone, the upper limit should be used.

[0041] From the above technical solutions, it can be seen that compared with the prior art, the present invention discloses a fertilization method for realizing the binary synergistic enrichment of zinc and selenium in wheat grains, and the technical effects achieved are as follows:

[0042] Based on years of multi-point experiments, the present invention has clarified the appropriate dosage of zinc application in the soil, the fertilization schemes for combined application with nitrogen, phosphorus, potassium fertilizers, and macro and micro elements such as humic acid, organic fertilizers, and calcium-magnesium-sulfur-silicon fertilizers, and determined the key technical parameters such as the appropriate concentration, water carrying capacity, spraying period, and number of times for foliar spraying of zinc and selenium with traditional plant protection machinery (small sprayers or backpack sprayers) and modern drones, thus innovatively forming a comprehensive soil-foliar fertilization technology for the binary synergistic enrichment of zinc and selenium in wheat grains.

[0043] Large - area foliar zinc fertilizer spraying operations are carried out by drones. Among the foliar spraying parameters, especially the spraying concentration of zinc sulfate heptahydrate, it is much higher than that under the operation conditions of manual backpack sprayers / small sprayers and the foliar zinc fertilizer spraying concentration in the current "one spray, three defenses" drone operations for wheat (in fact, the zinc fertilizer spraying concentration parameters in "one spray, three defenses" are derived from the operation experience of manual backpack sprayers / small sprayers). It can ensure the same effect as that under the operation conditions of manual backpack sprayers / small sprayers, greatly improve the zinc concentration in wheat grains while significantly improving the operation efficiency (saving time and effort). Therefore, it breaks through the inherent understanding of the traditional foliar zinc fertilizer spraying concentration, realizes the optimization, update and iterative upgrade of technical parameters, promotes the integration of agricultural machinery and agronomy, and forms the precise and efficient foliar zinc fertilizer spraying technology for drones.

[0044] Using the method of systems engineering, a comprehensive regulation technology has been formed from the soil to the leaves. There is a triple coordination among soil fertility improvement, stress resistance and yield increase, and the improvement of the trace element nutritional quality of wheat grains. Previous technologies only focused on one or two of these aspects and did not take them all into account simultaneously; it maximally exerts the effect of multiple mutual - benefit synergy among elements, maximally reduces / alleviates the antagonistic effect among elements, and realizes the five - element coordination of carbon, nitrogen, phosphorus, and trace elements (zinc and selenium);

[0045] Adopting a nutrition - oriented planting management method can not only greatly increase the concentrations of trace elements zinc and selenium in wheat grains, but also improve soil fertility (especially organic matter and zinc content) and enhance the stress resistance of crops.

[0046] Finally, through the coordinated regulation of macro, medium and micro elements, on calcareous calcareous alkaline soils, the wheat grain yield is increased by more than 10%, while the grain zinc concentration reaches more than 45 mg / kg, the grain selenium concentration reaches more than 150 μg / kg, and the concentrations of grain zinc and selenium both meet the nutritional fortification target values and the production requirements of zinc - rich and selenium - rich wheat; ultimately, the wheat is both high - yielding and nutritious, ensuring food quantity and nutritional security, and improving the trace element nutritional health level of people whose staple food is wheat. Brief Description of the Drawings

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0048] Figure 1 The attached drawing is a flow schematic diagram provided by the present invention.

[0049] Figure 2 The attached drawing is an experimental process diagram provided by the present invention.

[0050] Figure 3 The accompanying drawings are the on-site operation demonstration diagrams provided by the present invention.

[0051] Figure 4 The accompanying drawings are the on-site operation demonstration diagrams provided by the present invention. Detailed implementation manners

[0052] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] An embodiment of the present invention discloses a fertilization method for realizing the binary synergistic enrichment of zinc and selenium in wheat grains (for the process schematic diagram, see Figure 1 ). The raw materials not mentioned in the embodiments are all conventional raw materials;

[0054] For example: Jinan 17, commercially available from Shandong Luyan Agricultural Improved Variety Co., Ltd.;

[0055] The organic fertilizer can be selected as: Shandong Jiali Fertilizer Technology Co., Ltd., biological organic fertilizer, specification: effective viable bacteria count ≥ 200 million / g, organic matter ≥ 60% (execution standard: NY884-2012, registration certificate number: microbial fertilizer (2018) approval number (3337));

[0056] Calcium-magnesium-sulfur-silicon fertilizer: Yantai Zhongde Group Co., Ltd., brand, active calcium silicate magnesium, execution standard: NY / T 3830-2021; containing CaO: 25.0%, MgO: 8.0%, S: 8.0%, SiO2: 10.0%, Zn: 0.7%, B: 0.5%, Mo: 0.05%, functional substances: 0.05%;

[0057] Commercially available products that can meet similar planting requirements can be used;

[0058] The step methods not mentioned are all conventional methods, for example:

[0059] Operation conditions and requirements

[0060] (1) Before the first spraying, conduct a small-area pre-experiment to ensure that there is no poisoning phenomenon on the wheat leaves;

[0061] (2) It is preferably before 9:00 in the morning or after 16:00 in the afternoon; if it rains within 3h to 4h after spraying fertilizer, it needs to be re-sprayed when it is sunny, and the spraying concentration should be appropriately reduced;

[0062] (3) When selecting drones for spraying, the quality requirements of the drones should comply with the provisions of NY / T 3213, and the quality of drone operations should comply with the provisions of NY / T 4259.

[0063] Supporting technologies

[0064] The wheat straw is returned to the field in full, returning nutrients such as carbon, nitrogen, zinc, potassium and selenium accumulated in the aboveground part of the wheat to the soil. Other management measures are the same as those for general fields.

[0065] Example 1

[0066] A fertilization method for achieving synergistic enrichment of zinc and selenium in wheat grains (the tested wheat varieties are Jimai 22 and Jinan 17), comprising the following steps:

[0067] (1) Soil fertilization:

[0068] 1) Apply zinc fertilizer: (ZnSO4·7H2O) 2kg / mu as base fertilizer, apply once by tilling before sowing (to improve the bioavailability of trace element zinc in the soil);

[0069] 2) Application of base fertilizer: Compound fertilizer N-P2O5-K2O ratio of 25-10-10 (to control nitrogen and reduce phosphorus, enhance the "nitrogen-zinc synergistic effect", reduce / mitigate the "phosphorus-zinc antagonistic effect", low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer can be applied, with requirements of N ≥ 20%, 7% ≤ P2O5 ≤ 12%, K2O ≤ 13%), 45kg / mu, one-time application;

[0070] Humic acid (organic matter content 85%) 10kg / mu;

[0071] Organic fertilizer 50kg / mu;

[0072] Calcium-magnesium-sulfur-silicon fertilizer 10kg / mu

[0073] (The combination of the above base fertilizers can increase soil organic matter, improve physical, chemical and biological properties, increase the bioavailability of soil nutrients, and generally improve soil fertility);

[0074] 3) Topdressing:

[0075] Apply urea 15kg / mu during the greening / jointing stage, topdressing once;

[0076] (2) UAV (DJI UAV T20) foliar fertilizer spraying:

[0077] 21) Foliar spraying selenium on wheat by drone: At the heading stage of wheat, spray sodium selenite (Na2SeO3) at 5 - 10 g / mu (5 g / mu in this example), with a water volume of 5 - 10 L / mu (5 L / mu in this example), and add 0.01% (v / v) Tween 20; spray again 10 days after flowering, for a total of 2 sprays of selenium fertilizer.

[0078] 22) Foliar spraying zinc on wheat by drone: Spray 3 - 6% ZnSO4·7H2O at 3 - 5 L / mu (150 g / mu of ZnSO4·7H2O and 4 L / mu of water volume in this example) on the 5th, 15th, 20th, and 25th days after flowering respectively, add 0.01% (v / v) Tween 20, and the total operation is 4 times (the operation area is 5 mu).

[0079] To further optimize the technical solution: In step 2), replace the organic fertilizer with farmyard manure at 300 - 400 kg / mu (to replace part of the chemical fertilizer).

[0080] To further optimize the technical solution: In the topdressing stage of step 3), if wheat shows symptoms such as stunting and clustering, small leaves, leaf margin distortion or shrinkage, and yellowing from green on both sides of the leaf veins, ZnSO4·H2O / ZnSO4·7H2O should be topdressed in a timely manner at 1 - 2 kg / mu. In addition, in areas with integrated water and fertilizer conditions, during the seedling stage to jointing stage, topdress 1 - 2 times, with 0.5 kg / mu of ZnSO4·7H2O each time, applied simultaneously with urea or water-soluble fertilizers. When the irrigation water quality is alkaline, the pH value needs to be adjusted to the range of 5.5 - 6.0 before adding ZnSO4·7H2O.

[0081] To further optimize the technical solution: Foliar spraying fertilizer by drone: If wheat shows zinc deficiency symptoms at the seedling stage, spray ZnSO4·7H2O on the leaves, spray 1 - 2 times, with an interval of 5d - 7d between each spray; during the growth period, if it encounters adversity hazards such as drought, low temperature in late spring, and high temperature and dry hot wind in the later stage, which affect the normal growth and development of the plants, spray 1 - 2 times, with an interval of 5d - 7d between each spray.

[0082] To further optimize the technical solution: The step of foliar spraying zinc by drone can be replaced by using traditional plant protection machinery, manual backpack sprayers or small sprayers for foliar spraying zinc, with 0.3% - 0.5% zinc sulfate heptahydrate sprayed, and the fertilizer solution dosage is 40 L / mu - 50 L / mu.

[0083] To further optimize the technical solution: The step of foliar spraying zinc by drone can be replaced by using traditional plant protection machinery, manual backpack sprayers or small sprayers for foliar spraying zinc, with 0.3% - 0.5% zinc sulfate heptahydrate sprayed, and the fertilizer solution dosage is 40 L / mu - 50 L / mu.

[0084] Comparative experiment 1

[0085] Control: Only apply compound fertilizer with an N-P2O5-K2O ratio of 17-17-17 at 50 kg / mu as the base fertilizer, topdress 15 kg of urea per mu at the greening / jointing stage, without foliar fertilization, and other management measures are the same as in general fields.

[0086] The comparison of wheat grain yield and grain zinc and selenium concentrations after harvest is shown in Table 1:

[0087] Table 1 Effects of different fertilization treatments on wheat grain yield and grain zinc and selenium concentrations (Jinan, Shandong)

[0088]

[0089] Example 2

[0090] A fertilization method for achieving binary synergistic enrichment of zinc and selenium in wheat grains (the tested wheat variety is Jimai 44) includes the following steps:

[0091] (1) Soil fertilization:

[0092] 1) Application of zinc fertilizer: (ZnSO4·7H2O) 2 kg / mu is applied as basal fertilizer and incorporated into the soil by plowing once before sowing;

[0093] 2) Application of base fertilizer: The compound fertilizer N-P2O5-K2O ratio is 26-7-7, 50 kg / mu;

[0094] Humic acid (organic matter content 85%) 10 kg / mu;

[0095] Organic fertilizer 50 kg / mu;

[0096] Calcium-magnesium-sulfur-silicon fertilizer 10 kg / mu;

[0097] 3) Topdressing:

[0098] Urea 15 kg / mu is applied at the green-recovery / jointing stage, and topdressing is carried out once;

[0099] (2) Foliar fertilization by drone (DJI drone T20):

[0100] 21) Foliar spraying of selenium by drone: Sodium selenite 5 g / mu is sprayed at the heading stage of wheat, the water carrying capacity is 5 L / mu, and 0.01% (v / v) Tween 20 is added; it is sprayed again 10 days after flowering, and a total of 2 times of selenium fertilizer is sprayed;

[0101] 22) Foliar spraying of zinc by drone: At 5 days, 15 days, 20 days, and 25 days after flowering, zinc sulfate heptahydrate (ZnSO4·7H2O, 150 g / mu) is sprayed, 0.01% (v / v) Tween 20 is added, and the water consumption is 3 L / mu, with a total of 4 operations (the operation area is 1 mu).

[0102] Relevant drawings in the experimental process are shown in Figure 2 .

[0103] Comparative experiment 2

[0104] Control: Only compound fertilizer with an N-P2O5-K2O ratio of 26-7-7 was applied as base fertilizer at 50 kg / mu. At the green-recovery / jointing stage, 20 kg of urea was top-dressed per mu. There was no foliar fertilization, and other management measures were the same as those in general fields.

[0105] The comparison of wheat grain yield and grain zinc and selenium concentrations after harvest is shown in Table 2:

[0106] Table 2 Effects of different fertilization treatments on wheat grain yield and grain zinc and selenium concentrations (Heze, Shandong)

[0107]

[0108] Example 3

[0109] A fertilization method for achieving binary synergistic enrichment of zinc and selenium in wheat grains (the tested wheat variety is Jimai 22) includes the following steps:

[0110] (1) Soil fertilization:

[0111] 1) Application of zinc fertilizer: (ZnSO4·7H2O) was applied at a base application rate of 3 kg / mu and incorporated into the soil by one-time plowing before sowing;

[0112] 2) Application of base fertilizer: Compound fertilizer with an N-P2O5-K2O ratio of 26-10-8 was applied at 50 kg / mu;

[0113] Humic acid (organic matter content 85%) was applied at 20 kg / mu;

[0114] Organic fertilizer was applied at 100 kg / mu;

[0115] Calcium-magnesium-sulfur-silicon fertilizer was applied at 20 kg / mu.

[0116] 3) Top-dressing:

[0117] At the green-recovery / jointing stage, 15 kg of urea was applied per mu and top-dressed once;

[0118] (2) Foliar fertilization by drone (DJI drone T20):

[0119] 21) Foliar spraying of selenium by drone: Sodium selenite was sprayed at 5 g / mu during the wheat heading stage, with a water-carrying capacity of 5 L per mu, and 0.01% (v / v) Tween 20 was added; it was sprayed again 10 days after flowering, for a total of 2 sprays of selenium fertilizer;

[0120] 22) Foliar spraying of zinc by drone: Zinc sulfate heptahydrate (ZnSO4·7H2O, 200 g / mu) was sprayed on the 5th, 15th, 20th, and 25th days after flowering, with 0.01% (v / v) Tween 20 added and a water consumption of 5 L / mu, for a total of 4 operations (the operation area was 20 mu).

[0121] The relevant attached figures in the experiment are shown in Figure 3, 4 .

[0122] Comparison Test 3

[0123] Control 1: The compound fertilizer N-P2O5-K2O with a ratio of 20-26-8 is applied as basal fertilizer at 50 kg / mu, and 35 kg / mu of compound fertilizer (N-P2O5-K2O: 30-0-5) is topdressed per mu at the green-reverting / jointing stage. There is no foliar fertilization, and other management measures are the same as those in general fields.

[0124] Control 2: Compared with Example 3, some steps and fertilization are omitted. Specifically:

[0125] Zinc fertilizer (ZnSO4·7H2O) is applied at 3 kg / mu as basal application and incorporated into the soil by plowing once before sowing;

[0126] The compound fertilizer N-P2O5-K2O with a ratio of 26-10-8 is applied as basal fertilizer at 50 kg / mu;

[0127] Urea is applied at 15 kg / mu at the green-reverting / jointing stage;

[0128] Drone foliar spraying of selenium: Sodium selenite is sprayed at 5 g / mu at the heading stage of wheat, with a water-carrying capacity of 5 L / mu, and 0.01% (v / v) Tween 20 is added; it is sprayed again 10 days after flowering, for a total of 2 sprays of selenium fertilizer;

[0129] Drone foliar spraying of zinc: Zinc sulfate heptahydrate (ZnSO4·7H2O, 200 g / mu) is sprayed on the 5th, 15th, 20th, and 25th days after flowering respectively, with 0.01% (v / v) Tween 20 added and a water consumption of 5 L / mu, and the cumulative operation is 4 times (the operation area is 20 mu).

[0130] The experimental results are shown in Table 3:

[0131] Table 3 Effects of different fertilization treatments on wheat grain yield and grain zinc and selenium concentrations (Binzhou, Shandong)

[0132]

[0133] In summary:

[0134] (1) Moderately increase nitrogen and reduce phosphorus in compound / formulated / slow-release / controlled-release fertilizers during soil fertilization, involving specific ratios and dosage ranges of nitrogen, phosphorus, and potassium, to enhance the "nitrogen-zinc synergistic effect" and alleviate the "phosphorus-zinc antagonistic effect";

[0135] (2) Increase the application of trace elements during soil fertilization, including the simultaneous application of zinc and selenium elements, which can be added to compound / formulated / slow-release / controlled-release fertilizers or applied separately. It is necessary to specifically control the fertilization period, method, and dosage to generally improve the biological availability of the above trace elements in the soil;

[0136] (3) When applying humic acid and / or bio-organic fertilizer and / or other soil conditioners (calcium-magnesium-sulfur-silicon fertilizer) in soil fertilization, it is necessary to specifically control the fertilizer ratio and / or dosage to improve the physical-chemical-biological properties of the soil;

[0137] (4) In foliar fertilization, the use of drones for spraying is adopted. The key technical parameters such as the suitable periods, concentrations, dosages, and frequencies of spraying zinc, selenium, single-element, two-element, etc. by drones on a large area of leaves are determined. These technical parameters are significantly different from traditional spraying, forming a precise, efficient, and multi-element spraying technology for foliar micronutrients by drones;

[0138] (5) The present invention is a comprehensive management method for soil-foliar nutrients, which is an effective integration of various key individual technologies at the crop-soil system level. The above technical contents are indispensable and cooperate with each other. The macronutrients, medium nutrients, and micronutrients are precisely matched, morphologically compatible, and multi-element synergistic.

[0139] In this specification, each embodiment is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0140] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fertilization method for achieving synergistic enrichment of zinc and selenium in wheat grains, characterized in that: The following steps are involved: (1) Soil fertilization: 1) Apply zinc fertilizer; 2) Application of base fertilizer: Application of low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer, with the requirements of N ≥ 20%, 7% ≤ P2O5 ≤ 12%, K2O ≤ 13%); Humic acid; Organic fertilizer; Calcium-magnesium-sulfur-silicon fertilizer; 3) Top dressing; (2) UAV foliar fertilizer spraying: 21) UAV foliar spraying of selenium: Spraying selenium fertilizer on wheat during heading period; 22) Drone zinc foliar spraying: spraying zinc fertilizer.

2. The fertilization method according to claim 1, characterized in that: Step 1) Specifically, ZnSO4·7H2O is applied as a base at 2-3 kg / mu, and applied once by tilling before sowing; Step 2) low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer: compound fertilizer N-P2O5-K2O ratio is 25-10-10, 26-7-7 or 26-10-8, 45-50 kg / mu, applied once; Organic matter content 85% humic acid: 10-20kg / mu; Organic fertilizer 50-100 kg / mu; Calcium-magnesium-sulfur-silicon fertilizer application: 10-20 kg / mu; 3) Top dressing: Apply urea at a rate of 10-15 kg / mu during the greening / jointing period, and apply once.

3. The fertilization method according to claim 2, characterized in that: Step 21) spraying sodium selenite 5-10 g / mu, with a water carrying capacity of 5-10 L / mu, and adding v / v 0.01% Tween 20; spraying once again 10 days after flowering, for a total of 2 times of spraying of selenium fertilizer; Step 22) is specifically as follows: spray 3-6% Zn SO4·7H2O 3-5 L / mu, add v / v 0.01% Tween 20, accumulating 4 times at 5 days, 15 days, 20 days and 25 days after flowering.

4. The fertilization method according to claim 3, characterized in that: Step 2) Replace organic fertilizer with farmyard manure at 300-400 kg / mu.

5. The fertilization method according to claim 4, characterized in that: Step 3) During the topdressing stage, if wheat shows symptoms of dwarfing, small leaves, twisted or wrinkled leaf edges, and both sides of the leaf veins turning from green to yellow, apply ZnSO4·H2O / ZnSO4·7H2O 1-2kg / mu in time; In areas with integrated water and fertilizer conditions, topdressing is done 1 to 2 times from the seedling stage to the jointing stage, each time with 0.5 kg / mu of ZnSO4·7H2O, applied simultaneously with urea or water-soluble fertilizers; When the irrigation water is alkaline, the pH value needs to be adjusted to the range of 5.5 to 6.0 before adding ZnSO4·7H2O.

6. The fertilization method according to claim 5, characterized in that: Step (2) spraying fertilizer on the leaves by drone: If the wheat seedlings show symptoms of zinc deficiency, spray ZnSO4·7H2O on the leaves 1 to 2 times, with an interval of 5 to 7 days between each spraying. If the wheat seedlings encounter drought, low temperature and late spring cold, high temperature and dry hot wind in the late growth period, which are adverse conditions that affect the normal growth and development of the plants, spray 1 to 2 times, with an interval of 5 to 7 days between each spraying.

7. The fertilization method according to claim 6, characterized in that: The steps of spraying zinc on the leaves by drone can be replaced by spraying zinc on the leaves with traditional plant protection machinery, manual backpack sprayers or small spraying pots. Spray 0.3%~0.5% ZnSO4·7H2O, the amount of fertilizer liquid is 40L / mu~50L / mu.

8. Application of the fertilization method according to any one of claims 1 to 7 in agricultural production.

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